In a development that should send a chill down the spine of every citizen of St. Louis – especially considering the city’s efforts to revitalize its violence-plagued downtown – a sinkhole spontaneously appeared in the city’s downtown, swallowing a car that had been parked street side.

And even more concering, city officials say they have no idea how it happened.

Vincent Foggie, of the city’s water division, said the hole was missing mounds of dirt that normally support the road’s asphalt-topped concrete. He called such voids large enough to swallow a vehicle a rarity in the city.

“We don’t know what happened,” Foggie said. “I have no idea where the dirt went.”

St Louis resident Jordan Westerberg parked his car on sixth street downtown near the railway exchange building on Thursday morning as he and his fiancée headed to an early morning workout at a gym nearby.

When he returned shortly before 7 a.m. local time, his Toyota Camry was nowhere to be found. Westerberg and his fiancée said they figured it had been towed.

Then, they saw a gathering of street workers near their parking space, tipping them off that something wasn’t right. That’s when Westerberg, 25, found the vehicle in the gaping hole – about 20 feet (6 meters) deep and 8 to 10 feet (2.5 to 3 meters) across – that took up the entire southbound lane of the street, next to a vacant building expected to feature apartments, office space and retail, according to the Associated Press.